21869984 has 12 divisors (see below), whose sum is σ = 43056594. Its totient is φ = 10934976.

The previous prime is 21869983. The next prime is 21869989. The reversal of 21869984 is 48996812.

It can be written as a sum of positive squares in only one way, i.e., 19114384 + 2755600 = 4372^2 + 1660^2 .

It is not an unprimeable number, because it can be changed into a prime (21869983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 341687 + ... + 341750.

Almost surely, 2^21869984 is an apocalyptic number.

It is an amenable number.

21869984 is a deficient number, since it is larger than the sum of its proper divisors (21186610).

21869984 is an equidigital number, since it uses as much as digits as its factorization.

21869984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 683447 (or 683439 counting only the distinct ones).

The product of its digits is 248832, while the sum is 47.

The square root of 21869984 is about 4676.5354697682. The cubic root of 21869984 is about 279.6508573387.

The spelling of 21869984 in words is "twenty-one million, eight hundred sixty-nine thousand, nine hundred eighty-four".